MCCULLOCH The official McCulloch thread

[Al Smith]

i think this model is slightly different from what we had on the U-boats but then again I'm trying to visualize something from 50 years ago .This model was from my dumpster diving at work because all that out dated test equipment was thrown away .Oh did I ever make out like a fat rat doing that activity .

 

[Lnk]

i think this model is slightly different from what we had on the U-boats but then again I'm trying to visualize something from 50 years ago .This model was from my dumpster diving at work because all that out dated test equipment was thrown away .Oh did I ever make out like a fat rat doing that activity .

Never seen one of those. Looks like it is in good shape. Thanks for sharing.

 

[edju1958]

Back onto the Mac trac.Yesterday my son & I went to my older brother's to cut up a pile of logs that he had since 2017.They were still fairly solid under the 1st in.of crust.I took my Stihl mS310 to leave with him as his 290 is ailing.I also took my PM 700 & my son's PM 55.The 700 ran well,but after a while the chain started getting dull,so I started up the 55.I made about 3 cuts & then it suddenly just quit.I figured the condenser took a dump.Today I pulled the plug to check for spark & found a piece of debris in between the electrode & the ground strap.After I cleaned the plug & checked for spark (it had great spark) I put the plug back in & it fired right up.I've only seen the debris in the plug like that once before on a video on YouTube.I love an easy fix.

 

[heimannm]

Ed - my 2-10G used to to that on a fairly regular basis, cleaned the plug a few times and eventually it got over it. I was thinking it was perhaps some remnants of leaded fuel in the system, I have seen some McCulloch bulletins recommending against leaded fuel and the illustrations/drawings they showed in the bulletins of "lead balls" looked just like the formations on the spark plug of my 2-10G.

On the other hand, my Husqvarna BV125 routinely developes a bridge on the plug, looks more like a whisker than a ball, clean the plug and good to go for another hour or two.

Mark

 

[Squareground3691]

Anyone modify a PM 800 exhaust , it’s pretty silly and none performance for the saw , other than mounting another exhaust muffler on it from another Mac .

 

[Al Smith]

Not an 800 but an 805 with an early model 850 engine .The 850 had a curved bottom muffler with believe it or not a reed cover that wasn't rusted closed .All I can say is it runs great .

 

[Squareground3691]

Not an 800 but an 805 with an early model 850 engine .The 850 had a curved bottom muffler with believe it or not a reed cover that wasn't rusted closed .All I can say is it runs great .

It baffles me to know end, how engineers come up with such a design , as the PM800 muffler absolutely terrible.

 

[Al Smith]

I don't know what the thinking on those screened discharge type mufflers came from .It certainly wasn't designed for performance ,perhaps quieter ?It has the wrong shape to be a pressure can and it's dumped into a squared bottom which would certainly restrict the flow the way I see it .

 

[Squareground3691]

Not an 800 but an 805 with an early model 850 engine .The 850 had a curved bottom muffler with believe it or not a reed cover that wasn't rusted closed .All I can say is it runs great .

Was curious, thinking maybe the 850 would fit on the 800 but probably not .

 

[Al Smith]

It's basically the same engine with a few exceptions .However an example .The original 805 had peeled chrome so I found a needled block from I think an 850 .The mag coil either had to be shimed out or the mounting tabs filed off some to get the mag coils centered with the flywheel magnets .I screwed that up with a straight gas prime from not paying attention to what I was doing. So I found a rather rough looking 850 with a good engine rather inexpensive on flea bay and that's how it ended up . On the bones of the 850 it screwed up the piston but not the block which is all I need to build up another 82 cc Mac .Weather that will ever happens time will only tell .

 

[Squareground3691]

It's basically the same engine with a few exceptions .However an example .The original 805 had peeled chrome so I found a needled block from I think an 850 .The mag coil either had to be shimed out or the mounting tabs filed off some to get the mag coils centered with the flywheel magnets .I screwed that up with a straight gas prime from not paying attention to what I was doing. So I found a rather rough looking 850 with a good engine rather inexpensive on flea bay and that's how it ended up . On the bones of the 850 it screwed up the piston but not the block which is all I need to build up another 82 cc Mac .Weather that will ever happens time will only tell .

Really can’t figure out , what the Mac engineers were thinking when they designed the muffler exhaust, it’s terrible, big heat sink under the motor, with terrible flow, and does nothing to enhance its performance or efficiency.

 

[heimannm]

The "longer fin flywheel" is the 18 fin version that only fits the PM800, 805, DE80, and PM8200 saws with the shorter crankshaft.



I think the improved 3rd port boot is this one.



Mark

 

[Al Smith]

McCulloch Motors were once the leading edge but they certainly did some odd things at times .About that muffler you'd be surprised how much that style of the curved bottoms enhance the way they run .I've got a curved bottom from an early 10-10 on a 6-10 which is 70 cc's right hand start not to be confused with the 610 model .
Fact I'm going to do the same on a later model 10-10 I'm going to build up to run on the 3 cube class at "saw fest " which goes out to include 54 cc's .Mean time I'll need to hunt through my parts boxes for another muffler with a curved bottom .It's not if but rather where is it .

 

[Al Smith]

That mention of a longer and more fins reminds me of bucking up almost 6 cords of large ash one day in 95 degree heat and me over 60 years old .I alternated between a Mac 700 and a Stihl 038 Mag that was ported .They both did great but the 700 on a shut down for fuel would over heat the ignition causing it to fail .Obviously not enough air flow which when it cooled off it fired right up .

 

[Maintenance Chief]

Really can’t figure out , what the Mac engineers were thinking when they designed the muffler exhaust, it’s terrible, big heat sink under the motor, with terrible flow, and does nothing to enhance its performance or efficiency.

I modified mine , by cutting the entire front half of the muffler off with the exception of 1" to fold over and braze closed like an envelope. While not necessarily a performance modification it did eliminate the extreme amount of heat generated by the muffler. It has plenty of air flow around the motor and runs significantly cooler.
I thought about drilling some holes in the metal stand that is covered by screen but it runs well now and has very little restriction from the muffler.
I tried wrapping it with header wrap but it's such and odd shape it didn't fit well and it restricted air flow across the fins.
I know that I posted pics somewhere but I can't find them and I removed them from my phone to USB just don't know where that is?

 

[Maintenance Chief]

Here's some pictures from under the saw on the recoil side , as you can see its got quite a bit of air space that used to be muffler.
I still have some header tape under the muffler on the foot pad.
Blazed folds.

 

[Al Smith]

On my previous post about the 700 ignition fail I've had that happen years before on a PM 610.It would refuse to start after a fuel up until it cooled off .About drove me bonkers .

 

[NeSurcaster]

Man those 850's are sweet, definitely in my top 2 favorite saws I own. It helps that Mark rebuilt it w/ NOS parts, looks/acts like new. Love the sound and the performance, I run a 28" full skip and it's hard to get it to bog down. I'm sure it would pull full comp just fine I just prefer the less cutters to file when I hit somethin.
If I could just find a 32" .063 bar I'd be really happy... I tried years ago but never found one for sale.
Same for the sp60 mark built, almost bulletproof. Side to side against my 562 the super pro is noticeably smaller but very torquey. 562 is a little tough on the under cut due to it's high revving design, it likes to bog if you don't go full throttle while starting your under cut.

 

[Squareground3691]

Man those 850's are sweet, definitely in my top 2 favorite saws I own. It helps that Mark rebuilt it w/ NOS parts, looks/acts like new. Love the sound and the performance, I run a 28" full skip and it's hard to get it to bog down. I'm sure it would pull full comp just fine I just prefer the less cutters to file when I hit somethin.
If I could just find a 32" .063 bar I'd be really happy... I tried years ago but never found one for sale.
Same for the sp60 mark built, almost bulletproof. Side to side against my 562 the super pro is noticeably smaller but very torquey. 562 is a little tough on the under cut due to it's high revving design, it likes to bog if you don't go full throttle while starting your under cut.

Yea , Mcculloch was way ahead of it time back in the day. especially those 80cc class saws , but unfortunately all good things come to an end, and not always in a good way.

 

[Al Smith]

With a good sharp chain a good running 82 cc Mac does not have a problem with full comp on a 32" bar .